Tanning extract from peat.



. UNITEDSTATES PATENT OFFICE.

ERNEST EDWARD MUNRO PAYNE, or A LEsBU YQENQLAND, liss cnoa'or ONE-HALFTO WILLIAM HENRY STAYNES, JOHN HARDY SMITH, AND 'WALTER HENRY s'runensor .LEIGESTER, ENGLAND.

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Application filed September 26, 1904. Serial No. 226,024.

To all whom it may concern:

Be it known that I,"ERNnsr EDwARD MUNRo PAYNE, a subject of th King ofEngland, residing at Aylesbury, in the county of Buckingham, England,have invented certain new and useful Improvements in Tanning Extractsfrom Peat, of which the follow.-

(liquor is then treated with a suitable quantity of acid and this yieldsa product which is a somewhat diluted extract capable of producinleather.

If esired, a solid leather producing extract may be obtained, either byevaporation of the diluted extract described above or, when dealing withinsoluble modifications of the extract, by adding a sufficient quantityof acid to the resulting liquor until complete precipitation takesplace, when the extract can be separated out and used if desired, in

conjunction with certain solvent salts of neu- I tral composition suchfor example as sodium acetate.

In treating skins to produce leather in accordance with this invention,it is essential that the extract should be used in conjunction with anacid. The liquors containing the extract may be neutralized by theaddition of a suitable acid before the skins are placed therein or thenecessary acid treatment may take place subsequently.

In order to produce leather of good coinmercial quality according tothis invention, the skins are prepared in the usual way for tanning andthey may be brought by suitable treatment into an acid condition. Theyare-then submitted to the action of the extract or material hereindescribed by any suitable known treatment, and eather is thus obtained.The skins, however, may be left in or b rought Specification '01:Letters Patent.

mg the genera rocess of' handling and Patented Sept. 29, 1908.

to a-basic or alkaline condition and treated with the extract, beingfinally converted into leather by a subsequent acid treatment. Theherein described extracts may also be used in what is known ascombination tanning, 'i. 5. where several leather-producing agents areemployed together, and a very reat v'aricty of valuable and usefulleather 1s produced by various combinations, some by simultaneous othersby consecutive employments of the various tannages used it beingessential, according to this invention,

that the leather should be treated by the extract and by an acid.

The followin are specific examples involvrinciples of this invention,but the materia s and pro ortions would of necessity be varied, as t eyare in every leather-making process according to the requirements of themanufacturer.

A known quantity of disintegrated, dried.

or wet peat istaken (this of course varies in composition according to ae and locality).

The amounts of total soli s and ash con-.

tained in a sample are estimated. As in the ordinary process of tanncrsbark leachin for every thousand pounds of total solirs minus ashcontained in the eat, there is added one thousand gallons 0 caustic sodasolution at the ordinary temperature (of 1% strength NaHo) Afterdigesting for twentyfour hours, the liquor is drained as, returnedto-the top of the vat and a further twentyfour hours is allowed toinsure the solution of the leather-producing principles contained in thepeat. This marc is then drained, pressed and the resulting liquor iscollected.

(1) This g li'quor is treated with a solution of sulfuric acid (oil ofvitriol) in such a proportion as will saturate the whole of the sodiumbase existing in theliquid as determined by analysis. -A thick magma isproduced which wheniilter-pressed and dried Will yield a product whichwhen dissolved isv until only the free alkali, if any, is neutralized.his then evaporated to a syrupy consistency for purposes of transit orconcentra-.

tion and is immediately available for use as a leatherreducing agent.

(3) T e liquor is treated with acetic acid 5 until almost the whole ofthe sodium base, combined or free, existing in the liquor is neutralizedand the resulting liquor is immediately available for use asaleather-producing a ent." The exact amount of soda re- 10 quire for thepeat can, of course, be determined by a simple preliminary test, itbeing borne in mind that as the moisture in the peat varies from say 30%to 80% the dilution of the caustic soda will be correspondingly Theamount of acid required for the treatment say of 1-000 gallons ofresulting liq-n01 either to neutralize the free alkalinity 'or to ltated; separating the precipitate and neutralize the total alkalinity isascertained by titration of a sample.

What I claim as my invention and desire to secure by Letters Patent is Aprocess of preparing a leather-producing extract by comminutin peat,macerating it with a solution of caustic alkali, filtering andtreatingthe liquid with sulfuric acid until the solid leather-producingextract is reci iliseo V'- in it in a solution of sodium acetate.

testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ERNEST EDWARD MUNRO Witnesses:

WILLIAM H.- BALLANTYNE, HARRY B. BRIDGES.

PAYNE.

